Electrical connectors are used in a wide variety of applications including, frequently, at the terminus of the electrical cables that are used to connect separate pieces of equipment. Applications using such cables may range from heavy-duty industrial applications, to telecommunications, to home electronics. As one example, many consumer-oriented electronics systems are component systems rather than integrated systems. In other words, instead of having all portions of a particular electrical system in one physical unit, where the internal components would be connected by internal wiring, it is very common to have each of the components manufactured as a separate individual physical device that can be purchased separately and then connected together by the consumer.
For consumer-oriented applications especially, the connections should be easy to make and to disconnect, although they also have to be reliable. Since the consumer may buy various system components from different manufacturers, some tolerance in the design of the interconnecting elements is also desirable. When these components are connected to one another, cables may be used to make the connection. The cables may be supplied along with each individual system component, or they may be separately purchased on an as-needed basis. Separately-purchased cables are often available in higher-quality versions than those provided with the units, and are frequently produced by a manufacturer other than the one supplying the basic system components. Small deviations in size are possible.
In this context, electrical cables include one or more wires or other conductors enclosed in some kind of dielectric or insulating material. A typical cable for use in home entertainment systems includes an insulated central or axial wire surrounded by a mesh conductor, with this assembly surrounded by another, exterior insulating material. The cables are typically flexible, and may be of varying length depending on the application for which they are intended. Otherwise identical cables may be sold in a variety of selected lengths so that individual consumers may choose the one that is most suitable. Typically, this means that the consumer will arrange their electrical components, such as those associated with a TV or stereo system, and then determine the length of cable needed to connect the various components to each other. Often these cables are supplied with the components that will need to be attached to one another, but frequently the cables are purchased separately as well.
At one time, it was common to use wires or cables that simply terminated. The consumer would select a cable of appropriate length, then strip away a small amount of the insulating material and wrap the exposed conductor portion around a screw, or insert it into a clamp to complete the connection. More recently, however, in order to make for more convenient use by the consumer, each end of the cable is now typically equipped with a suitable connector. These cable connectors may come in a wide variety of configurations. As might be expected, however, standards evolved or were promulgated for certain commonly-used electrical connectors so that a wide range of components may be interconnected using the same basic cables. While there are many different types, a few standard connectors are very popular.
One popular type of electrical connector is often referred to as an RCA connector or, more recently, as an audio-video (or simply A/V) connector. Cables featuring these connectors are frequently used to connect different components in, for example, a home entertainment system. Such systems may typically have at least three or four components, but may have as many as a dozen or more. Sometimes more than one cable will be required to connect any two components together. Note, however, that while these connectors will be primarily discussed as attached to the ends of cables, there must also be a compatible connector on the system component or other device being connected.
FIG. 1 is an illustration of a typical A/V connector pair 100 as viewed from the side. Each connection must, of course, be made of two corresponding connectors that, while not identical, are made to join with each other to form a secure electrical connection. (Making both corresponding connectors identical to each other, or nearly so, is possible but rare in current industry practice for this particular application.) In the case of A/V connectors, one-half of this connection pair will herein be referred to as a “jack,” and the other half will be referred to as a “plug”, although other names (for example “female” and “male”) may be used as well. In the example of FIG. 1, the A/V cable jack is designated 150, and the plug 110. In many cases, a particular cable will have a plug at each end, with each plug connectable with a jack located on a system component. At other times, of course, a cable might also have two jacks, one on each end, or a jack on one end and a plug on the other.
In the connector pair of FIG. 1, jack 150 is at the end of cable 149, which in this example (and as described above) includes two conductors separated from each other by an insulating material, and this whole assembly is surrounded by an insulating exterior. Jack 150 includes a body 155 that not only houses the electrical connection (not shown) between the cable conductors themselves and the electrically conductive portions of the jack connector, but also provides a convenient place for the consumer to grip the connector when connecting or disconnecting it. For additional security, a gripping surface 156 is formed in body 155 by scoring an enlarged portion of its exterior. If body 155 is molded from a thermoplastic material, as is not atypical, gripping area 156 may also be produced in the molding process. A grip may also be a separate component that has been fabricated from a suitable material and in some fashion secured into place. In the connector jack 150 of FIG. 1, a flexing section 157 is also formed in the body 155 to permit the end of the body to flex as the cable 149 is moved from side to side.
Protruding from body 155 is a barrel 160, which is made of a conducting material that is electrically connected to one of the cable 149 conductors within body 155. The barrel is typically cylindrical in shape, though other shapes may be used as well so long as they are compatible with the desired plug type. The interior of the barrel 160 is filled with a dielectric material that forms a central recess in which a second conductor is disposed (see FIG. 2). This second conductor will sometimes be referred to as part of a receptacle.
Corresponding portions of the A/V cable plug 110 will make contact with these conductors. In the illustration of FIG. 1, connector plug 110 is disposed at the termination of cable 109. Body 115, as in the body 155 of jack 150, houses the electrical connections (not shown) between the conductors of plug 110 and those of cable 109. In the plug 110 of FIG. 1, these conductors are sleeve 120 and probe 130. To form connection, jack 110 and plug 150 are moved into engagement in the direction of the arrows above FIG. 1. The manner in which the two connectors mate when engaged may be easily understood by reference to FIG. 2.
FIG. 2 is an isometric view of the A/V connector pair 100 of FIG. 1 (reoriented to show certain features). Referring first to connector jack 150, it can here be seen that the interior of barrel 160 includes a dielectric cylinder 162, which functions to structurally separate the two connector conductors. Dielectric cylinder 162 forms an opening 163, in which is disposed receptacle conductor 164. Correspondingly, in it can be seen in FIG. 2 that probe 130 of connector plug 110 extends from the middle of floor 121 of sleeve 120. More specifically, floor 121 forms an opening 123. Dielectric ring 122 is disposed within opening 123, and itself forms an opening 124 through which extends probe 130. Dielectric ring 122 provides for electrical isolation between the probe 130 and the floor 121 of sleeve 120.
When the connector pair is assembled (as indicated in FIG. 1), the outer wall 161 of barrel 160 connects electrically with the interior wall 126 of sleeve 120, thereby forming one of the two electrical connections (typically the ground). The second electrical connection is formed when probe 130 is received in the opening 163 and contacts the receptacle conductor 164. In addition, the mechanical interaction of sleeve 120 and barrel 160, and of probe 130 and receptacle connector 164, tend to secure the jack 150 and plug 110 together in an assembled configuration (not shown) until a sufficient separating force is applied to pull them apart. Naturally, the closer in size these corresponding components are, the more secure the fit. Although a barrel or probe that is too large would resist being received into the sleeve or receptacle, respectively, if they are relatively no smaller than necessary for the connection to occur, they will tend to require a greater applied force to separate the plug and jack. Up to a reasonable limit, greater security is preferred, and helps to ensure a good-quality electrical connection as well.
Unfortunately, these corresponding parts of the connectors may vary somewhat in size from manufacturer to manufacturer and from application to application. This may be intentional, or may be due to manufacturing tolerances that allow for the variation. Too great a deviation, of course, will result in a connector not being able to connect at all, or in a loose connection that is too easily broken. Over time, wear and plastic deformation may also occur, degrading the quality of the connection. Easily broken or faulty connections such as these often mean that the entire cable terminated at the connector will have to be replaced. Not only does the consumer in this case have to purchase another cable, but replacement can be difficult where, as is not uncommon, the cables and the connections they provide are hidden in hard-to-access locations. In some cases, faulty connections may even cause damage to other system components as well. For these reasons, an improved connector design is needed so as to accommodate small variations in the size of various components due, for example, to manufacturing tolerance differences or wear and tear. The connector of the present invention provides just such a solution.